Clear Lake
Martin County, Minnesota267 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Clear Lake. Here is what has been measured.
- Hypereutrophic
- 7 ft max depth
- Public access
- Limited data
Clear Lake in Martin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 74.5 µg/L. Chlorophyll-a (algae): 52.1 µg/L. Maximum depth: 7 ft. Surface area: 267.34 acres.
Clear Lake is a 267-acre highly nutrient-loaded hypereutrophic lake in Martin County, Minnesota with a maximum depth of 7 feet. The lake supports 12 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing. Compared to the 11 other monitored lakes in Martin County, Clear Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-16. Methodology: how these readings are compared.
Clear Lake covers about 270 acres in Martin County. It has one public boat landing. The median ice-out date is March 21, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Clear Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Clear Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing12 species recorded
- Ice seasonIce-out around Mar 21
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Clear Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Clear Lake
These are the measurements Minnesota PCA publishes for Clear Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 1 ft of visibility. Phosphorus 74.5 µg/L. Chlorophyll-a 52.1 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 74.5µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 52.1µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Clear Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Clear Lake typically sits around 73°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 80°F) and coldest in May (about 55°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (55°F) to its warmest (80°F).
Typical surface water temperature by month, from 15 field readings (2025–2025) via the EPA Water Quality Portal. See the full Clear Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Clear Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,419,058 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
Max depth
7 ft
Surface area
267 acres
Shoreline
2.7 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
3 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,243 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Clear LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Clear Lake
Compare lakeside cabins, hotels, and vacation rentals near Clear Lake in Martin County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Clear Lake are listed below.
Top-rated places to stay near Clear Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Clear Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Clear Lake
Ice season
Typical ice-out
Mar 21
Earliest Mar 9, 2026 · Latest Apr 11, 2023
Typical ice-in
Dec 2
Earliest Nov 28, 2025 · Latest Dec 7, 2017
Most recent ice-out
Mar 9
2026
9 observations · Minnesota PCA ice records
Nearby Lakes in Martin County
Frequently asked questions about Clear Lake
Where is Clear Lake?
- Clear Lake is a lake in Martin County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Clear Lake?
- Clear Lake in Martin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 74.5 µg/L. Chlorophyll-a (algae): 52.1 µg/L. Maximum depth: 7 ft. Surface area: 267.34 acres.
Is Clear Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Clear Lake?
- Clear Lake typically sits around 73°F at the surface in September, from 15 EPA Water Quality Portal field readings (2025–2025). That is a typical value for the month, not a live reading.
How deep is Clear Lake?
- Clear Lake has a maximum depth of 7 feet. The lake covers 267.34 acres.
What fish are in Clear Lake?
- Fish species found in Clear Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, channel catfish, common carp, orangespotted sunfish, walleye, white crappie, white sucker, yellow bullhead, yellow perch. Clear Lake is located in Martin County, Minnesota.
When does Clear Lake thaw?
- Clear Lake typically has ice-out around Mar 21. Ice typically forms around Dec 2. The open water season is approximately 256 days.
Does Clear Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Clear Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,419,058 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Clear Lake?
- Clear Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Clear Lake. Public access is listed as yes.
Can I fish at Clear Lake?
- Clear Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Clear Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Martin County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Clear Lake
Other Lakes in Minnesota
Hypereutrophic Lakes in Minnesota
Where this data comes from
15 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA15 samples · 2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate